# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Carson River, East Fork
Water Body ID: | CAR6321007219980803164808
Water Body Type: | River & Stream

DECISION ID | 30475 | Region 6
Carson River, East Fork

Pollutant: | Total Dissolved Solids
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Three lines of evidence, two to evaluate COLD and one to evaluate MUN, are available in the administrative record to assess this pollutant. None of 16 samples exceed the MCL for protection of MUN. Five out of seven annual average datapoints exceed the site specific water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. For the 2010 listing cycle Regional Board staff found that the annual averages were based on limited data (between 1-5 samples/year), and this sampling frequency is not considered temporarily representative. For the 2010 listing cycle, USEPA assessed data against the applicable standards for both the annual average and 90th percentile and determined that both aspects of the standard are not achieved. 3. None of 16 samples exceeded the MCL for protection of MUN. Five of seven samples exceeded an annual average value for protection of COLD and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. For the 2010 listing cycle Regional Board staff found that the annual averages were based on limited data (between 1-5 samples/year), and this sampling frequency is not considered temporarily representative. The 2012 LOE did not indicate any additional exceedances and Regional Board staff still find that the exceedances associated with the 2010 LOE (4915) are based on limited data that are not temporally representative.

Line of Evidence (LOE) for Decision ID 30475, Total Dissolved Solids | Region 6
Carson River, East Fork
LOE ID: | 32227
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual averages for TDS for both years for this data set were below the Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-pecific objective for Total Dissolved Solids (TDS) in Lahontan Basin Plan Table 3-14, includes an annual average of 80 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 632ECR005 (East Fork Carson, at USGS gage blw Markleeville).
Temporal Representation: | Samples were collected between 6/29/2006 - 12/7/2006 and 1/10/2007 - 11/6/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 30475, Total Dissolved Solids | Region 6
Carson River, East Fork
LOE ID: | 4915
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 5
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled TDS under the Region 6 SWAMP program between 2002 and 2005. TDS concentrations in 16 samples reported as "residue" ranged from 45 to 118 mg/L. Annual averages (based on 1 to 5 samples per year) ranged from 81 to 112 mg/L. The highest average was based on a single sample. The annual average objective was exceeded in 5 of 5 years. In addition the calculated 90th percentile for the 16 samples was 115.4 mg/L, which is higher than the 90th percentile site specific objective of 100 mg/L. An additional 6 samples reported as "nonfilterable" TDS were collected in 2003 and 2004 (on the same dates as the "residue" samples. Concentrations in four samples were below the detection level; concentrations in the remaining samples were 10 and 93 mg/L.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
| USEPA Region 9 data summary for addition of total dissolved solids to California 2010 303(d) list for Carson River and Mammoth Creek in Lahontan Region
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site specific objective for Total Dissolved Solids (TDS) is an annual average of 80 mg/L and a 90th percentile value of 100 mg/L (Lahontan Basin Plan Table 3-14).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen samples reported as "residue" were collected over 5 years (2001 to 2005 at 1 to 5 samples per year). An additional 6 samples reported as "nonfilterable" were collected in 2004 and 2005.)
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 30475, Total Dissolved Solids | Region 6
Carson River, East Fork
LOE ID: | 4917
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled TDS under the Region 6 SWAMP program between 2001 and 2005. TDS concentrations in 16 samples ranged from 45 to 118 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Total Dissolved Solids (TDS) is 500 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen samples were collected over 5 years (2001 to 2005 at 1 to 5 samples per year).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 22786 | Region 6
Carson River, East Fork

Pollutant: | Boron
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the nine samples exceeds the California State Notification Level for protection of MUN use. Three annual average datapoints exceed the site-specific water quality objective, which is an annual average of 0.12 mg/L boron. Although this satisfies binomial model requirements for listing, listing is not recommended because the small number of samples per year does not capture seasonal and annual variation in flows and constituent concentrations. Also, except for borate fire retardants used in fighting wildfires, boron in this watershed comes from natural sources such as Grover Hot Springs. The overflow from the springs discharges to Hot Springs Creek, then to Markleeville Creek and the East Fork Carson River. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy.The two annual average exceedances that were associated with 2010 LOE #4890 were only based on one sample to calculate an annual average. The annual average exceedance associated with 2012 LOE #32233 was calculated based on 5 samples collected Aug-Dec 2007. None of these exceedance accurately capture the annual and seasonal fluctuations in boron concentrations and streamflow conditions. 3. None of the nine of samples exceeded the guideline (State Notification Level)and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. Three of the annual average datapoints exceeded the site-specific objective and this exceeds the allowable frequency in Table 3.1 but listing is not recommended because the small number of samples per year does not capture seasonal and annual variation in flows and constituent concentrations inputs of boron within this waterbody are likely due to natural sources. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. The limited samples per year to calculate an annual average does not capture seasonal and annual variation in flows and constituent concentrations inputs of boron within this waterbody are likely due to natural sources.

Line of Evidence (LOE) for Decision ID 22786, Boron | Region 6
Carson River, East Fork
LOE ID: | 21492
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 9
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled boron under the Region 6 SWAMP program between 2002 and 2004. Boron concentrations in nine samples ranged from 16 to 162 ug/L. The criterion was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California State Notification Level for boron is 1000 ug/L.
Objective/Criterion Reference: | Drinking Water Notification and Response Levels: An Overview
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Nine samples were collected between 2002 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. Boron in this watershed is likely to come from natural geothermal sources. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22786, Boron | Region 6
Carson River, East Fork
LOE ID: | 32233
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average of Boron for 2007 for this data set was 0.179 mg/L which exceeds the site-specific Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for Boron in the Lahontan Basin Plan page 3-40, states that the mean of monthly means for boron shall not exceed 0.12 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data was collected at the following station: 632ECR005 (East Fork Carson, at USGS gage below Markleeville).
Temporal Representation: | Samples were collected between 8/2/2007 - 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22786, Boron | Region 6
Carson River, East Fork
LOE ID: | 4890
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled boron under the Region 6 SWAMP program between 2002 and 2004. Boron concentrations in nine samples ranged from 16 to 162 ug/L. The annual average objective was exceeded in 2 out of 4 years.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific water quality objective is an annual average of 0.12 mg/L (= 120 ug/L) with a 90th percentile value of 0.250 mg/L (= 250 ug/L). See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Nine samples were collected between 2002 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. Boron in this watershed is likely to come from natural geothermal sources. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 22983 | Region 6
Carson River, East Fork

Pollutant: | Chloride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence,two LOES to evaluate COLD and one LOE to evaluate MUN, are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples (the 2010 LOE associated with COLD relied on 12 samples collected over a 4 year period to calculate annual averages) and do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of the 12 samples exceeded the MCL for MUN, and none of 6 annual average datapoints exceeded the site-specific, annual average objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. 5. In May 2009, the Lahontan Water Board issued the California Department of Parks and Recreation Waste Discharge Requirements Order No. R6T-2009-0025 which requires discharges from the Grover Hot Springs State Park (1) comply with receiving water limitations for chloride and other constituents. Discharges from Grover Hot Springs discharge to Hotsprings Creek, which is tributary to Markleeville Creek, which is tributary to Carson River East Fork. Grover Hot Springs does chlorinate its cold pool. Discharge water is dechlorinated before being discharged to HotSprings Creek but any residual chloride discharges, that may reach the East Fork of the Carson River should be controlled through implementation of best management practices required by Order No. R6T-2009-0025.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22983, Chloride | Region 6
Carson River, East Fork
LOE ID: | 32240
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average for CL for this data set does not exceed the Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for Chloride in the Lahontan Basin Plan page 3-40, states that the annual average for Chloride shall not exceed 4.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 632ECR005 - East Fork Carson, at USGS gage below Markleeville.
Temporal Representation: | Samples were collected 6/29/2006 - 12/7/2006 and 1/10/2007 - 11/6/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22983, Chloride | Region 6
Carson River, East Fork
LOE ID: | 4892
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled chloride under the Region 6 SWAMP program between 2002 and 2005. Chloride concentrations in 12 samples ranged from 0.33 to 4.39 mg/L. Annual average concentrations did not exceed the objective.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objectives are an annual average of 4.0 mg/L and a 90th percentile value 6.0 mg/L. See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS gage below Markleeville, was sampled.
Temporal Representation: | Twelve chloride samples were collected over 4 years (2002 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22983, Chloride | Region 6
Carson River, East Fork
LOE ID: | 4893
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled chloride under the Region 6 SWAMP program between 2002 and 2005. Chloride concentrations in 12 samples ranged from 0.33 to 4.39 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituent" objective. The MCL for chloride is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Twelve chloride samples were collected over 4 years (2002 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 20986 | Region 6
Carson River, East Fork

Pollutant: | Dissolved oxygen saturation
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Two of the 18 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy.Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. Two of the 18 samples exceeded the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3/11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 20986, Dissolved oxygen saturation | Region 6
Carson River, East Fork
LOE ID: | 5728
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 14
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled dissolved oxygen under the Region 6 SWAMP program between January 2002 and August 2005. Percent saturation values in 14 quarterly samples ranged from 98 to 130 percent. The objective was not violated. However, sampling frequency was insufficient to define the natural percent saturation regime or to detect change.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's regionwide narrative objective for dissolved oxygen provides that percent saturation shall not be depressed more than 10 percent nor shall the minimum dissolved oxygen concentration be less than 80 percent of saturation.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS gage below Markleeville, was sampled.
Temporal Representation: | Fourteen quarterly measurements of percent saturation were taken over 4 years (2002 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20986, Dissolved oxygen saturation | Region 6
Carson River, East Fork
LOE ID: | 44398
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 2 of 4 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective states that the dissolved oxygen concentration shall not be less than 80 percent of saturation.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 8/2/2007-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 23412 | Region 6
Carson River, East Fork

Pollutant: | Fecal Coliform
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Four lines of evidence, three to evaluate Rec-1 and one to evaluate MUN, are available in the administrative record to assess this pollutant. One sample associated with the 2010 LOE exceeded the objective for protection of MUN. The samples collected to evaluate protection of Rec-1 were compared to two separate, but related objectives. One of the 2010 samples associated with the 2010 LOE for Rec-1 exceeded both of the fecal coliform objectives: the fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml and nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. None of the samples associated with the 2012 LOE (5 samples total evaluated against two separate LOEs) exceeded the objectives for protection of REC-1. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. The water quality objective calls for at least 5 fecal coliform samples collected within a 30-day period. 3. One of 7 samples exceeded the water quality objective for MUN and one of 12 samples exceeded the objective for REC-1, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 23412, Fecal Coliform | Region 6
Carson River, East Fork
LOE ID: | 32256
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the five samples exceeded the Fecal Coliform objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration shall not exceed more than 40/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected from station 632ECR005 East Fork Carson, at USGS gage below Markleeville.
Temporal Representation: | The samples were collected once a month from August to December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 23412, Fecal Coliform | Region 6
Carson River, East Fork
LOE ID: | 34862
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the five samples exceeded the fecal coliform objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. Water Quality Control Plan for the Lahontan Region.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected from station 632ECR005 East Fork Carson, at USGS gage below Markleeville.
Temporal Representation: | The samples were collected once a month from August to December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 23412, Fecal Coliform | Region 6
Carson River, East Fork
LOE ID: | 21495
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled the East Fork Carson River under the Region 6 SWAMP program between 2003 and 2005. Six of 7 fecal coliform samples had estimated bacteria counts, and the seventh was reported as greater than 240 colonies per 100 mL, exceeding the objective.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Seven samples (1 to 4 per year) were taken between 2003 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 23412, Fecal Coliform | Region 6
Carson River, East Fork
LOE ID: | 21493
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled the East Fork Carson River under the Region 6 SWAMP program between 2003 and 2005. Six of 7 fecal coliform samples had estimated bacteria counts, and the seventh was reported as greater than 240 colonies per 100 mL, exceeding the objective.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Seven samples (1 to 4 per year) were taken between 2003 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 30486 | Region 6
Carson River, East Fork

Pollutant: | Fluoride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 one line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of Two samples exceeded the objectiveand this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 30486, Fluoride | Region 6
Carson River, East Fork
LOE ID: | 33341
Pollutant: | Fluoride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Zero of 2 samples exceeded the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Fluoride is 2.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 632ECR005 (East Fork Carson, at USGS gage blw Markleeville).
Temporal Representation: | Samples were collected between 8/2/07 and and 11/6/07.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 30485 | Region 6
Carson River, East Fork

Pollutant: | Iron
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 one line of evidence is necessary to assess listing status. Two lines of evidence, one each evaluating the COLD and MUN beneficial uses, are available in the administrative record to assess this pollutant. Zero of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of samples exceeded the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 one line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of two samples exceeded the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 5 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Line of Evidence (LOE) for Decision ID 30485, Iron | Region 6
Carson River, East Fork
LOE ID: | 44267
Pollutant: | Iron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Iron.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | The Red Book states that based on field observations principally, a criterion of 1.0 mg/L iron for freshwater aquatic life is believed to be adequately protective (National Recommended Water Quality Criteria 2009).
Guideline Reference: | National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 8/2/2007-11/6/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 30485, Iron | Region 6
Carson River, East Fork
LOE ID: | 44285
Pollutant: | Iron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Iron.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's Objective for Municipal and Domestic Supply uses of inland surface waters states that waters designated as MUN shall not contain concentrations of chemical constituents in excess of the maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL). This is based upon drinking water standards specified in the following provisions of Title 22 of the California Code of Regulations which are incorporated by reference into the Water Quality Control Plan: Table 64431-A of Section 64431 (Inorganic Chemicals), Table 64431-B of Section 64431 (Fluoride), Table 64444-A of Section 64444 (Organic Chemicals), Table 64449-A of Section 64449 (Secondary Maximum Contaminant Levels-Ranges). The maximum contaminant level listed in Table 64449-A for Iron is 0.3 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 8/2/2007-11/6/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22797 | Region 6
Carson River, East Fork

Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 47 samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22797, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Carson River, East Fork
LOE ID: | 21486
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled the East Fork Carson River under the Region 6 SWAMP program between 2001 and 2005. One of 16 quarterly samples was an estimated value, and 8 were below the detection level. Concentrations of nitrite plus nitrate in the remaining samples ranged from 0.002 to 0.02 mg/L The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite plus nitrate is 10 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen quarterly samples were taken between 2001 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22797, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Carson River, East Fork
LOE ID: | 44308
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 31
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 0 of 31 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Maximum Contaminant Level for nitrate + nitrite (as N) that is incorporated by reference in the Water Quality Control Plan, Lahontan Region is 10.0 mg/L (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 6/29/2006-11/6/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 20987 | Region 6
Carson River, East Fork

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the diel, seasonal and annual variability expected in streamflows and dissolved oxygen concentrations in streams of the Lahontan Region. 3. None of 19 samples exceeded the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 20987, Oxygen, Dissolved | Region 6
Carson River, East Fork
LOE ID: | 32272
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Zero of 5 samples exceeded the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable site specific water quality objective from p. 3-9 of the Lahontan Basin Plan for the East Fork Carson River Hydrologic Unit states that the dissolved oxygen concentration shall not be below 7.0 mg/L at any time.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 632ECR005 - East Fork Carson, at USGS gage blw Markleeville.
Temporal Representation: | Samples were collected between August and December 2007
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 20987, Oxygen, Dissolved | Region 6
Carson River, East Fork
LOE ID: | 4899
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 14
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled dissolved oxygen under the Region 6 SWAMP program between 2002 and 2005. Dissolved oxygen concentrations in 14 samples ranged from 8.4 to 12.2 mg/L. The objective was not violated.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | For waters designated COLD and SPWN, the 1 day minimum objective is 8 mg/L dissolved oxygen (Lahontan Basin Plan Table 3-6).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Fourteen dissolved oxygen measurements were taken over 4 years (2002 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 28343 | Region 6
Carson River, East Fork

Pollutant: | Phosphorus
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Five of the seven annual average datapoints exceed the water quality objective. However, listing is not recommended because there is a quality assurance problem with the data. Additionally, the data associated with 2010 LOE and the data are not temporally representative since annual averages were calculated on limited samples (between 1-4 samples used to calculate an annual average). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy due to an error in the SWAMP QAPP regarding holding times for total phosphorus samples.(The two samples associated with the 2012 LOE (a total of 12 samples for 2006 and 22 samples collected in 2007) did not meet proper QA because the holding times did not comply with SWAMP requirements.) 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples, or those collected less frequently, do not capture the full range of variation in streamflows and constituent concentrations expected in streams of the Lahontan Region. 3. Five out of 7 annual average datapoints exceeded the site specific objective and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy but listing is not recommended because the the information is not sufficient because of quality assurance issues. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are being exceeded because there is a quality assurance problem with the data, and the data are not temporally representative.

Line of Evidence (LOE) for Decision ID 28343, Phosphorus | Region 6
Carson River, East Fork
LOE ID: | 34485
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 2 of 2 annual averages exceed the water quality objective for Total Phosphorus. Annual averages were calculated by water year starting in June 2006 through December 2007. Total Phosphorus was calculated by summing Orthophosphate as P and Phosphorus as P data. Phosphorus as P data were averaged when they were collected on the same day. Five pairs were summed and then averaged for 2007 before comparing with the annual average Total Phosphorus objective. One pair was available for 2006 to compare with the annual average Total Phosphorus objective. The data were not used in cases where only Phosphorus as P was available without Orthophosphate.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-14 of the Basin Plan states that the water quality objective for Total Phosphorus for East Fork Carson River is an annual average objective of 0.02 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at East Fork Carson, at USGS gage blw Markleeville (632ECR005).
Temporal Representation: | Samples were collected from June 2006 through December 2007.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan
Line of Evidence (LOE) for Decision ID 28343, Phosphorus | Region 6
Carson River, East Fork
LOE ID: | 21498
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 3
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled total phosphorus under the Region 6 SWAMP program between 2001 and 2005. Concentrations in 4 of 16 quarterly samples were below the detection level. The remainder of the samples ranged from 0.018 to 0.201 mg/L. Annual averages were below the detection level in 2 of 5 years. Averages in the remaining 3 years ranged from 0.027 to 0.087 mg/L; all three averages exceeded the objective.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for total phosphorus in the East Fork Carson River includes an annual average of 0.02 mg/L and an annual 90th percentile value of 0.03 mg/L. See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen quarterly samples (1 to 5 per year) were collected between 2001 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | Sampling and analysis were done according to the SWAMP QAPP. However, in July 2009 an error was discovered in the QAPP related to holding times for total phosphorus samples that affects the validity of data for the Lahontan Region The holding time for samples that are not acid-preserved.should be 48 hours rather than 28 days as indicated in the QAPP. "Low level" phosphorus analyses, without acid preservation, are used in the Lahontan Region's SWAMP program. .
QAPP Information Reference(s):

DECISION ID | 32002 | Region 6
Carson River, East Fork

Pollutant: | Salinity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. None of the sample (an annual average value calculated from 21 samples) exceed the water quality objective. Salinity data in parts per thousand was converted to mg/L so data could be compared against the site specific objective for Total Dissolved Solids at Carson River, East Fork of 80 mg/L to determine whether the salinity data provided in this data set protect COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None sample (an annual average calculated from 21 samples) exceeded the site specific objective of 80 mg/L for TDS and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32002, Salinity | Region 6
Carson River, East Fork
LOE ID: | 34504
Pollutant: | Salinity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average of the 21 samples of 52.3 mg/L did not exceed the site specific objective of 80 mg/L.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Regional Board will consider sitespecific adjustments to the objectives for wetlands (bacteria, pH, hardness, salinity, temperature, or other parameters) as necessary on a case-by-case basis. The site specific objective for Total Dissolved Solids at Carson River, East Fork is 80 mg/L and will be used to assess the salinity data provided in this data set.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples collected from the 632ECR005 station.
Temporal Representation: | Samples collected approximately twice a month from January 2007 to December 2007
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 32003 | Region 6
Carson River, East Fork

Pollutant: | Sodium Adsorption Ratio (SAR)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. The single sample exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy.Quarterly water samples, used to calculate an annual average, do not capture the full range of seasonal and annual variation in streamflows and constituent concentrations expected in streams of the Lahontan Region. 3. The single sample exceeded the site specific objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32003, Sodium Adsorption Ratio (SAR) | Region 6
Carson River, East Fork
LOE ID: | 32275
Pollutant: | Sodium Adsorption Ratio (SAR)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Agricultural Supply
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average for year 2007 was 3.28 and does exceed the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable site specific water quality objective from the amended Lahontan Basin Plan for the East Fork Carson River states that the annual average SAR (sodium adsorption rate) should not exceed 2.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| 2006. Amendments to the Water Quality Control Plan for the Lahontan Region: Revised Sodium-Related Standards for the Carson and Walker River Watersheds. Adopted October 12, 2006 under Resolution R6T-2006-0047
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 632ECR005 - East Fork Carson, at USGS gage blw Markleeville.
Temporal Representation: | Data was collected during August 2007 and November 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 20738 | Region 6
Carson River, East Fork

Pollutant: | Specific Conductance
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the 47 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. None of 47 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 20738, Specific Conductance | Region 6
Carson River, East Fork
LOE ID: | 4905
Pollutant: | Specific Conductance
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey measured specific conductance under the Region 6 SWAMP program between 2001 and 2005. In 16 field measurements, specific conductance ranged from 48 to 168 uS/cm. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen measurements of specific conductance were taken over 5 years (2001 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20738, Specific Conductance | Region 6
Carson River, East Fork
LOE ID: | 44378
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 31
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 0 of 31 samples exceed the criterion for Conductivity(Us).
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Lahontan Region for specific conductance is 900 uS/cm (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 1/10/2007-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22588 | Region 6
Carson River, East Fork

Pollutant: | Sulfates
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence, two to evaluate COLD and one to evaluate MUN, are available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level (MCL) for protection of the MUN beneficial use. Six of the six samples exceed the criteria for protection of COLD, which is based on an annual average of 4 mg/L sulfate. The annual average exceedances associated with the 2010 LOE # 4910 were calculated using 1-4 samples collected over the year and are not temporally representative of seasonal and annual variations in sulfate concentrations and streamflow conditions within this watershed. One of the annual average exceedances associated with the 2012 LOE (2006 dataset) were based on samples collected between June-Dec. The annual average exceedance associated with the 2012 LOE (2007 dataset) was calculated from 22 samples that were collected throughout the entire year and are considered temporally representative. Even though the 2007 dataset is comprehensive, listing is not recommended at this time because of the overall weakness of the dataset, which does not accurately represent annual fluctuations of sulfate. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. The exceedances associated with the 2010 LOE #4910 were based on samples that were collected quarterly, or less frequently, and should not be considered with the decision since they do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region (Staff find it is acceptable not to include this LOE in the Final Use Rating). 3. None of 12 samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. Six of 6 annual average datapoints exceeded the site-specific objective. Though this satisfies the minimum sample number exceedancs of Table 3.2 for listing, staff are not considering the exceedances associated with the 2010 LOE #4910 in the final use rating. The two annual average exceedances associated with the 2012 LOE #32262 is an insufficient sample size is to determine with the power and confidence of the Listing Policy if standards are not met, as a minimum of either (1) 26 samples, or (2) greater than or equal to 5 exceedances of the objective with less than 26 samples is needed for application of Table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. 5. In May 2009, the Lahontan Water Board issued the California Department of Parks and Recreation Waste Discharge Requirements Order No. R6T-2009-0025 which requires discharges from the Grover Hot Springs State Park (1) comply with receiving water limitations for sulfate and (2) not cause a violation of the numeric water quality objectives specified for the East Fork of the Carson River. Order No. R6T-2009-0025 also requires the discharger to develop and implement a Best Management Practices (BMP) Plan, which must include site-specific BMPs to reduce or eliminate the discharge of pollutants to waters of the State and of the United States. These measures should reduce sulfate loading to the East Fork of the Carson River that are associated with discharges from Grover Hot Springs State Park.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22588, Sulfates | Region 6
Carson River, East Fork
LOE ID: | 4910
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 4
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled sulfate under the Region 6 SWAMP program between 2002 and 2005. Sulfate concentrations in 12 samples ranged from 1.3 to 14.8 mg/L. The annual average objective was exceeded in 4 out of 4 years.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objectives for sulfate in the East Fork Carson River are an annual average of 4.0 mg/L and an annual 90th percentile value of 8.0 mg/L. See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Twelve sulfate samples were collected over 4 years (2002 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22588, Sulfates | Region 6
Carson River, East Fork
LOE ID: | 4911
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled sulfate under the Region 6 SWAMP program between 2002 and 2005. Sulfate concentrations in 12 samples ranged from 1.3 to 14.8 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California MCLs apply to ambient waters under the Lahontan Basin Plan's Chemical Constituents objective. The MCL for sulfate is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Twelve sulfate samples were collected over 4 years (2002 to 2005) .
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22588, Sulfates | Region 6
Carson River, East Fork
LOE ID: | 32262
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The samples collected for years 2006 and 2007 did exceed the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | From the Lahontan Basin Plan Table 3-14, the water quality objective for sulfate in this water body is an annual average of 4 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at station 632ECR005 - East Fork Carson, at USGS gage blw Markleeville.
Temporal Representation: | The samples were collected 6/29/2006 - 12/7/2006 and 1/10/2007 - 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 21176 | Region 6
Carson River, East Fork

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Cold Freshwater Habitat (COLD) beneficial use. The objective does not include specific numerical limits for protection of the COLD use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. Two lines of evidence are available to support this decision. There are not enough temperature samples to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist. Because temperature samples were collected only quarterly, weekly and monthly average data are not available for comparison with guidelines in the scientific literature for the temperature requirements of sensitive aquatic species such as salmonids, as directed in Listing Policy Section 6.1.5.9.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because available data are insufficient for assessment under Listing Policy Sections 3.10 and 6.1.5.9. to evaluate whether applicable water quality standards are being exceeded or not.

Line of Evidence (LOE) for Decision ID 21176, Temperature, water | Region 6
Carson River, East Fork
LOE ID: | 4920
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled water temperature under the Region 6 SWAMP program between 2001 and 2005. Temperatures in 16 field measurements ranged from 0 to 17 degrees Celsius.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The temperature objective in the Lahontan Basin Plan states: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered. Temperature objectives for COLD interstate waters and WARM interstate waters are as specified in the 'Water Quality Control Plan for Control of Temperature in The Coastal and Interstate Waters and Enclosed Bays and Estuaries of California' including any revisions."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, below Markleeville, was sampled.
Temporal Representation: | Sixteen temperature measurements were taken over 5 years (2001 to 2005 at 1 to 5 samples per year).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21176, Temperature, water | Region 6
Carson River, East Fork
LOE ID: | 44135
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 21
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Water Temperature.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective for all surface waters states the following: The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 1/10/2007-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22616 | Region 6
Carson River, East Fork

Pollutant: | Total Nitrogen as N
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the annual average datapoints exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 7 annual average datapoints exceeded the site-specific objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22616, Total Nitrogen as N | Region 6
Carson River, East Fork
LOE ID: | 32328
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | None of 2 annual averages exceeded the water quality objective for total nitrogen. Annual averages were calculated by water year starting in June 2006 through November 2007. Total nitrogen was calculated by summing nitrate + nitrite as N data with TKN data when they were collected on the same day. Thirty-one pairs were summed and then averaged before comparing with the annual objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-14 of the Basin Plan states that the water quality objective for nitrogen, total for East Fork Carson River is an annual average objective of 0.2 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at East Fork Carson, at USGS gage blw Markleeville (632ECR005).
Temporal Representation: | Samples were collected from June 2006 through November 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22616, Total Nitrogen as N | Region 6
Carson River, East Fork
LOE ID: | 21497
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled total nitrogen under the Region 6 SWAMP program between 2001 and 2005. Concentrations in 9 of 16 quarterly samples were estimated values. The remainder of the samples ranged from 0.063 to 0.15 mg/L. Numerical annual averages could not be calculated for 2001 through 2004 due to the estimated values. The annual average objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for total nitrogen in the East Fork Carson River includes an annual average of 0.20 mg/L and an annual 90th percentile value of 0.30 mg/L. See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005..
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 23411 | Region 6
Carson River, East Fork

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | The Lahontan Basin Plan's narrative pH objective is an antidegradation-based objective that requires that there be no change greater than 0.5 pH units in waters designated for the Cold Freshwater Habitat (COLD) or Warm Freshwater Habitat beneficial uses. (A pH range of 6.5 to 8.5 units applies to "all other waters.") Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. Two lines of evidence is available to support this decision. There are not enough pH samples to establish baseline conditions (including diel, seasonal, annual and interannual variations) or to detect changes in the pH regime due to controllable factors, if such trends exist. This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 15 samples exceeded the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the data are insufficient to establish baseline and trend conditions as required under Listing Policy section 3.10.

Line of Evidence (LOE) for Decision ID 23411, pH | Region 6
Carson River, East Fork
LOE ID: | 32259
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | There were 21 samples with pH ranging from 7.7 to 8.9. The normal ambient pH level for this water body is unknown and so it is unknown whether any exceedences occured.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units." (Lahontan Basin Plan).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Station 632ECR005 - East Fork Carson, at USGS gage blw Markleeville.
Temporal Representation: | Samples were collected between 1/10/2007 and 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 23411, pH | Region 6
Carson River, East Fork
LOE ID: | 4898
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 15
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled pH under the Region 6 SWAMP program between 2002 and 2005. In 15 field samples, pH ranged from 7.7 to 8.3 units.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The objective for pH in the Lahontan Basin Plan states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Fifteen pH measurements were taken over 4 years (2002 to 2005).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 22838 | Region 6
Carson River, East Fork

Pollutant: | Arsenic
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence, involving a single sample, are available in the administrative record to assess this pollutant. The sample does not exceed the California Toxics Rule (CTR) standards or the California Maximum Contaminant Level (MCL).. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the CTR standards or the MCL. However, the minimum sample number requirements of Table 3.1 of the Listing Policy were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22838, Arsenic | Region 6
Carson River, East Fork
LOE ID: | 4891
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled arsenic under the Region 6 SWAMP program. One sample had an arsenic concentration of 7.2 ug/L. The MCL was not violated.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for arsenic is 10 ug/L (effective November 28, 2008).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | One sample was collected on 11/24/2004.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. Arsenic in this watershed is likely to be from natural volcanic or geothermal sources. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22838, Arsenic | Region 6
Carson River, East Fork
LOE ID: | 4889
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | The U.S Geological Survey sampled arsenic under the Region 6 SWAMP program. One sample had an arsenic concentration of 7.2 ug/L. The CTR standards were not violated.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule (CTR) freshwater aquatic life standards for arsenic are as follows: 4-day average = 150 ug/L 1 hour average = 340 ug/L
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS gage below Markleeville, was sampled.
Temporal Representation: | One sample was collected on 11/24/2004.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. Arsenic in this watershed is likely to be from natural volcanic or geothermal sources. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 31949 | Region 6
Carson River, East Fork

Pollutant: | Nitrite
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the 31 samples exceed the water quality objective (MCL of 1 mg/L for nitrite as N). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 31 samples exceeded the objective (MCL) and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 31949, Nitrite | Region 6
Carson River, East Fork
LOE ID: | 44328
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 31
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, East Fork to determine beneficial use support and results are as follows: 0 of 31 samples exceed the criterion for Nitrite as N.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, East Fork was collected at 1 monitoring site [ East Fork Carson, at USGS gage blw Markleeville]
Temporal Representation: | Data was collected over the time period 6/29/2006-11/6/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22543 | Region 6
Carson River, East Fork

Pollutant: | Phosphate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sample, is available in the administrative record to assess this pollutant. No biological data are available for assessment of compliance with the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. No biological data are available to determine whether the single sample exceeded the water quality objective. This sample doe not meet the minimum sample number requirement of Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available and the minimum sample number requirements of the Listing Policy are not met.

Line of Evidence (LOE) for Decision ID 22543, Phosphate | Region 6
Carson River, East Fork
LOE ID: | 21499
Pollutant: | Phosphate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled the East Fork Carson River under the Region 6 SWAMP program. A single sample for dissolved PO4 was collected on November 18, 2003. The concentration was 0.019 mg/L.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no site-specific numerical objectives for phosphate for the East Fork Carson River. The regionwide narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | One sample was collected on November 18, 2003.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 21995 | Region 6
Carson River, East Fork

Pollutant: | Sediment
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: The Lahontan Basin Plan's narrative water quality objective is an antidegradation based objective that provides that there shall be no increases in suspended sediment concentrations or loads. This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy, which deals with trends in water quality. One line of evidence, based on quarterly sampling, is available in the administrative record to assess this pollutant. It includes 16 suspended sediment concentration values and 16 suspended sediment load values calculated from instantaneous discharge measurements. Suspended sediment concentrations and loads are dependent on flows and can change rapidly over a short time during storm or snowmelt runoff events. Quarterly samples are insufficient to capture these short term events and therefore are insufficient to define natural background suspended sediment concentrations and loads, or to detect trends. Listing Policy Section 3.10 requires that natural background conditions be established. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. Sampling frequency was insufficient to establish natural background conditions and therefore does not meet the requirements of Listing Policy Section 3.10. 3. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle. RWQCB staff continue to conclude that the water body-pollutant combination should not be placed on the section 303(d) list because available information and data do not meet the requirements of Listing Policy section 3.10.

Line of Evidence (LOE) for Decision ID 21995, Sediment | Region 6
Carson River, East Fork
LOE ID: | 4907
Pollutant: | Sediment
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled suspended sediment under the Region 6 SWAMP program and did load calculations based on concurrent flows between 2001 and 2005. Sixteen instantaneous discharge flow measurements ranged from 29 to 2500 cubic feet per second. Suspended sediment concentration in 16 samples ranged from 1 to 297 mg/L. Suspended sediment loads in 16 calculations ranged from 0.08 to 2000 tons per day. (The highest concentration and load occurred during the spring runoff season in May 2005.)
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The narrative objective for suspended sediment in the Lahontan Basin Plan states: "The suspended sediment load and suspended sediment discharge rate of surface waters shall not be altered in such a manner as to cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen samples were taken, and sixteen load calculations were done, between 2001 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 22536 | Region 6
Carson River, East Fork

Pollutant: | Total Kjeldahl Nitrogen (TKN)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollution
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether of the chemical samples exceeds the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. No biological data are available for assessment of compliance with the objective for biostimulatory substances. The chemical data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no biological data available for assessment of compliance with the applicable water quality objective.

Line of Evidence (LOE) for Decision ID 22536, Total Kjeldahl Nitrogen (TKN) | Region 6
Carson River, East Fork
LOE ID: | 21491
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled sulfate under the Region 6 SWAMP program between 2001 and 2005. One of 16 quarterly samples for TKN was an estimate; concentrations in the other samples ranged from 0.04 to 0.19 mg/L
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There is no site-specific numeric objective for Total Kjeldahl Nitrogen (TKN) for the East Fork Carson River. The Lahontan Basin Plan's narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 22911 | Region 6
Carson River, East Fork

Pollutant: | Turbidity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. A total of 16 samples were collected and results were used to evaluate protection of the MUN and COLD beneficial uses. Separate lines of evidence were prepared for data expressed as NTU and NTRU. The two types of units are measured differently and are not directly comparable. There are no specific state or federal standards or criteria for turbidity expressed as NTRU. Three of the samples expressed as NTU exceed the Maximum Contaminant level. The Lahontan Basin Plan's narrative turbidity objective is a non-degradation objective, and sample numbers are insufficient to establish baseline conditions or detect trends as required under Listing Policy Section 3.10. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the diel, seasonal and annual variability expected in streamflows and turbidity levels in streams of the Lahontan Region. 3. Three of 12 samples expressed as NTU exceeded the Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. It is not possible to determine whether the narrative turbidity objective was exceeded because the requirements of Listing Policy Section 3.10 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle. RWQCB staff continues to conclude that the water body-pollutant combination should not be placed on the section 303(d) list because one of the applicable water quality standards is not being exceeded and the data are insufficient to determine compliance with the other.

Line of Evidence (LOE) for Decision ID 22911, Turbidity | Region 6
Carson River, East Fork
LOE ID: | 21551
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled the East Fork Carson River under the Region 6 SWAMP program between 2004 and 2005. Two of 4 turbidity measurements expressed as NTRU were below the detection level. The others were 2.2 and 40 NTRU. The highest value was recorded during a high flow spring runoff event in May 2005.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards or criteria for turbidity expressed as NTRU for the projection of aquatic life..
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville was sampled.
Temporal Representation: | Four turbidity measurements recorded as NTRU were taken in 2004 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville"station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22911, Turbidity | Region 6
Carson River, East Fork
LOE ID: | 4923
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 3
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey measured turbidity under the Region 6 SWAMP program between 2001 and 2004. Turbidity in 12 samples ranged from below the detection level to 14 NTU..Three of the 12 samples reported as NTU exceeded the MCL.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient surface waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for turbidity is 5 NTU.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Twelve turbidity measurements expressed as NTU were taken between 2001 and 2004..
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22911, Turbidity | Region 6
Carson River, East Fork
LOE ID: | 4903
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey sampled the East Fork Carson River under the Region 6 SWAMP program between 2004 and 2005. Two of 4 turbidity measurements expressed as NTRU were below the detection level. The others were 2.2 and 40 NTRU. The highest value was recorded during a high flow spring runoff event in May 2005.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards or criteria for turbidity expressed as NTRU for the projection of human health.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville was sampled.
Temporal Representation: | Four turbidity measurements recorded as NTRU were taken in 2004 and 2005.
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville"station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22911, Turbidity | Region 6
Carson River, East Fork
LOE ID: | 4922
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S Geological Survey measured turbidity under the Region 6 SWAMP program between 2001 and 2004. Turbidity in 12 samples ranged from below the detection level to 14 NTU.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The regionwide turbidity objective in the Lahontan Basin Plan states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, East Fork Carson River at USGS Gage below Markleeville, was sampled.
Temporal Representation: | Twelve turbidity measurements expressed as NTU were between 2001 and 2004 (at 1 to 5 samples per year).
Environmental Conditions: | The East Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in an area transitional to the Great Basin ecoregion. The "below Markleeville" station is downstream of subwatersheds contributing acid mine drainage, and downstream of Markleeville Creek, which is affected by geothermal drainage. In addition to the Cold Freshwater Habitat beneficial use, the river is designated for the Spawning, Reproduction and Development and the Rare, Threatened, or Endangered Species uses. The latter use reflects the presence of Lahontan and Paiute cutthroat trout.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):